Railway draft-gear.



R. A. FRENCH &. L. T. GIRDLBR.

RAILWAY DRAFT qua. APPLICATION FILED OUT 24, 1906 Patented Dec.28,1909

a snnms-sannzr 1.

INVE TOR wrrussses R. A. FRENCH & L. T. GIRDLBR. RAILWAY D FT GEAR.

APPLICATION I D OCT. 24, 1906. 944,321 Patented Dec. 28, 1909. sums-sum2.

R. A. FRENCH & L. T. GIR'DLER.

RAILWAY DRAFT GEAR.

I APPLICATION I'ILED OUTM, 1906 IIIIIIIIIIIIHHH'H I I II l i izyl lllwrmsssss I mvsu'rons.

m. Ami-Lasts COPY Sineeifieation of Letters Eatent.

D LOUIS T. GIRDLER, OF SEWICKLEY, PENNSYL- & MANUFACTURING 00., OFPITTSBURG,

N ENNSYLVANIA.

A 5.3' DRAFT-GEAR.

Patented Dec. 28, 1909i.

@eteber 24, 1906. Serial No. 340,345

e class of draft a fear hav- 1 applye springs through a l l N equalizethe piesao away with stops, l having two exerting a radial ethe form ofi av; bar, UllUA'til. conical spi idea) with their ends, and more at :9and.

(huddle son l'iear up ably reev face of the core are true cones, thecoils nearest the small end of the cone will reeeive the greater radialstrain, owing to their reater travel during the stroke. Inasniue li theradial strain will cause a peruianent set in the coils it carried beyondthe elastic limit, it is therefore necessary in such a form to soproportion the parts that the radial strain will not exceed the elasticlimit in the coils nearest the small end of the cone. Consequently thestrain upon the coils nearer the large end of the cone, must be farbelow the elastic limit, thus decreasin the resistance. lVe haveovercome this diilieulty by curving the surface of theconical memberinstead of making it a straight or true conical form. By making thiscurve sharper near the larger end of the cone and flatter near the smallend, We can con'ipensate for the greater travel of the smaller diametercoils, and cause a substantially uniform bursting strain upon all thecells. This may he used either upon a tandem TIQOIIH, as shown in Fig.1, or a single spring form, as shown in Fig. 2. Thus in l igr. Q2, 2 isthe yoke, 3 the draw bar, 4* the front follower 2111C 5* the rearfollower. The front follower is provided with the core which ispreferably cylindr' all or slightly, tapered in the part 8, while theremainder l0 is of general conical form, but with the surface curvedpreferably in some hyperbolic form. ln this case, the spring 7* hears atone end against the follower 4", and at the other end agaii'lst thefiller plate 11 whirl: recessed and provided with a central hole toreceive the end of the core.

in all the forms we prefer to provide sufiicient clearance space betweenthe spring or springs and the core, so that there will he no friction orradial strain through the first part of the stroke in either direction;95 while during the latter part of the stroke, the core exerts itsradial pressure upon the several coils of the spring during theircloslug against each other.

Fig, 3, we show a form substantially 100 like Fig. 1, except that thecones are. reversed in position, their larger ends being at the outerends of the springs. In this form, parts similar to Fig. 1 are markedwith .t' ar name ads with the letter b ap- 105 in such. case the fillerplates Ll at the outer ends of the springs may bedone away with, and thering 12 between the adjacent ends of the springs is preferably recessedto form seats, and provided with a central hole toi'eceive the ends ofthe conical cores. By the words conical or F cone in the specificationand claims, we intend to cover a core having a ,decreasing cross-sectionwhether its surface is in straight lines or curves.

The advantages of our invention result from the simplicity andcompactness of the device and the great increase in' resistance due tothe radial pressure of'the core. By

changing the angles of the core ti} the spring or springs we can varythe reslstanc'e and exert the radial pressure through the cue tirestroke or any desired part thereof.

Our device may be employed for a yielding resistance in ordnance or forother locations where such resistance is desired; andby the termdraft-riggin in our 5 ecifi cation and claims we inten to cover al suchforms whether pressure is applied in one or both directions. The featureofcompensating. for the greater stroke of some of the coils may be usedwith either single or tandem springs, and many other changes may be madewithout departing from the spirit and sec e of our invention.

We 0 aim 1. In a friction device for draft riggings and other purposes,a longitudinal spiral conical spring, and a conical device, one of saidparts fitting over the other to exert a radial pressure upon the spring,the conical device having portions of its frictional 's'urface ofdifferent pitch; substantially as described. v l g 2. In a frictiondevice for draft riggings and other purposes, a. longitudinal spiralspring, and a conical device in position to engage the spring andarranged to exert av radial pressure thereon, said device decreasing indiameter in different ratiosin different parts thereof to compensate forthe greater stroke of some of the coils; substan tially as described.

'3. In a friction device for draft riggings and other" purposes, alongitudinal s iral spring, and a conical core coacting t ere- With andarranged to exert a radial pressure thereon, said coredecreasing indiameter to a greater extent at its larger portions than at its smallerportions to compensate for the greater stroke of the coils' near itssmaller end; substantially as described.

' 4. In a friction device for draft riggipgs and other purposes alongitudinal spiral spring, and a conical core within the sprin andcoacting therewith to exert a radia pressure thereon, the face of saidcone being curved longitudinally; substantially as de-' scribed.

- 5. In a draft rigging, apair of spiral springs having spaced-apartcoils and arranged in tandem, and a pair of conical devices coactingwith the springs to exert a radial pressure thereon both on bufiing andpulling strains; substantially as described.

6. In a friction device for diaft riggings to exert a radial pressurethereon; substan tially' as described.

'7. In a fllctlOli device for draft riggings and other pufiposcs, a pairpf spiral springs.

having space apart coils and arran ed in tandem and each havingdecreasing iameter's' toward one end thereof, and apair of conical conescoacting with the springs to exert a radial pressure thereon, thesurfaces of said cones decreasing in diameter to different amountsthrough the different portions thereof to compensate for the greaterstroke of the coils near the small ends of thesprings; substantially asdescribed. 7 v

8. In a friction device for draft ri-ggings and other purposes, a pairof tandem spiral springs of conical shape and having spacedapart coils,said springs having their larger ends adjacent to each other, and a coreof' 9. In a friction device for draft riggings and other purposes, apairof tandem sprln s of con calshape having spaced-a art C01 s and havingtheir larger ends a'jacent to each other, and a core of general doubleconical shape with its largest diameter at its i central portion, saidcore having a-spacer between the inner ends of thesprings; spbstnntlallyas described.

10. In a friction device for draft riggings and other purposes, a pairof tandem spiral 'springshaving spaced-"apart coils, and conipul devicesarranged to exert a'fradial pressure upon the springs, said sprin shaving 7 a movable hearing at their smaller ends:

substantially as described.

11. In a friction 'device for draft riggings and other purposes, alongitudinal; spiral conical spring, and a. mechanical device arrangedto contact with the interior surface of said spring, the bearing surfaceof the device an the inner bearingsurfa ce of the spring being, ofdifferent contours; substantially as described. Q; 1 I

12. In a friction device for draft riggings and other purposes, alongitudinalfispiral spring, and a conical device arranged to contactwith and exert a radial. pressure upon the spiral spring, the innerfaces of the I coils being curved outwardly with resnect to the axis ofthe conical device; substantially as described.

13.-A ffrihion device for draft riggipgs and other purposes, comprisingtwo coactlng conical members having frictlonal surfaces arrangerhto vbebrought mto Contact wlth each other, said surfaces beiflg non-parallel vfor at least a portion of their length; substantially as described.

In testimony wh reegf, we nu e, heriihfi;

\Vitnesses: v

G120. B. BLEMING, ,JOHN MILLER.

